Swift 3 发送带有附件歧义表达式的电子邮件

Question

我正在尝试使用带有以下代码的 MFMailComposeViewControllerDelegate 设置电子邮件 View Controller :

let fileName = "test.csv"

   let path = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(fileName)

 if MFMailComposeViewController.canSendMail() {
            let emailController = MFMailComposeViewController()
            emailController.mailComposeDelegate = self
            emailController.setToRecipients(["testemail.com"])
            emailController.setSubject("Test Email")
            emailController.setMessageBody("Test Message", isHTML: false)
            emailController.addAttachmentData(NSData(contentsOfURL: path)!, mimeType: "text/csv", fileName: "test.csv")
            present(emailController, animated: true, completion: nil)
        }

上面在 addAttachmentData 行上抛出一个 error 是，

Type of expression is ambiguous without more context.

我错过了什么吗？

Answer 1

使用两个表达式而不是一个:

    let data = Data(contentsOf: path)!
 emailController.addAttachmentData(data, mimeType: "text/csv", fileName: "test.csv")